This invention relates to vehicle lamps and, in particular, to a vehicle lamp especially adapted for use on boat trailers. More specifically, but without restriction to the particular use which is shown and described, this invention relates to a submersible lamp assembly which when submerged under water maintains the interior of the lamp dry preventing water from contacting an electric lamp and socket assembly positioned within the lamp housing causing corrosion and/or bulb breakage, and preventing degradation of lamp photometrics.
When a boat is launched or retrieved from the water, the boat trailer upon which the boat is carried must be maneuvered into the water a sufficient distance to launch or retrieve the boat. In so doing the rear signal lamps utilized on the boat trailer are submerged under water during this procedure, and frequently remain submerged under water for substantial periods of time while the boat is maneuvered into position and aligned with the trailer so that it may be winched on the trailer and removed from the water.
Until the invention of a lamp fixture which utilized an air trapping principle, such as disclosed in U.S. Pat. No. 3,106,349, and U.S. Pat. No. 3,858,039, prior attempts had been made to seal the lamp housing to prevent water from entering. Such "sealing" attempts were generally unsatisfactory, and led to the inventions described in the afore-mentioned patents, as well as that of U.S. Pat. No. 4,281,367. Boat trailer lamps which incorporated the inventions of these three patents, eliminated the problems of bulb and bulb socket corrosion, bulb breakage caused by thermal shock, provided convenient tool-less access to replace burned out bulbs, and prevented the terminal connections between the lamp and the trailer wiring from being subjected to rust and corrosion.
Such prior art submersible lamps solved these problems. However, once these problems were resolved the standardization of such vehicle lighting became desirable for boat trailer manufacturers. The present invention permits a single basic rear signal lamp housing to be used on either the right rear or left rear of a vehicle by interchanging a modular lens and reflector assembly, and by a bulb and socket support bracket within the standardized housing. The lamp of the preferred embodiment can also function as either a left or right sidemarker or clearance lamp by substitution of a readily insertable bulb slide so that the same lamp housing may be used on either side of the trailer for all trailer widths. However, if the bulb and bulb socket are oriented in a vertical direction, such as illustrated in U.S. Pat. No. 3,858,039, as an example, the same bulb slide supporting structure can be used in the standardized housing to mount the bulb and bulb socket for use on either side of the trailer.